The present invention relates to a disposable elastic diaper which includes an initially molten film having laminated thereto an absorbent unit and an extensible fabric.
Disposable diapers, sanitary napkins, incontinent pads, and similar disposable articles have become commercially important. The structure of these articles is similar and generally has three basic components: a liquid-impermeable backing, an absorbent unit and a liquid-permeable facing. Generally, the backing is of a film such as a polyethylene film and typical prior art diapers are shown in U.S. Pat. No. Re. 26,151 and U.S. Pat. No. 3,612,055. Generally, the absorbent unit is smaller in size than the backing or the facing and is sandwiched between the backing and the facing, the latter two being laminated one to the other in the marginal portions. Frequently, the absorbent unit is a fluff batt of loosely compacted cellulosic fibers, such as woodpulp fibers.
Though the backing film, typically of polyethylene film, is liquid-impermeable it is frequently noisy and has a very slick feeling to it. Furthermore, the thin polyethylene films that are used tend to tear rather easily. Many attempts have been made to overcome these drawbacks. For instance, a diaper having a fibrous outer layer is shown in U.S. Pat. No. 3,779,246. All diapers formed in accordance with this patent have improved feel and appearance as compared to diapers having an exposed plastic sheet as the outermost layer. The fabric layer coupled with the necessary adhesive introduces additional thickness which in turn can impair flexibility.
Another problem with commercially available disposable diapers is the stability of the fluff batt. Many improvements have been made to stabilize the fluff batt. For instance, in U.S. Pat. No. 3,017,304 a paper-like densified skin is provided on the outermost side of the fluffed batt and in U.S. Pat. No. 3,938,522 densified regions, generally in the form of embossed lines, are present to both stabilize the fluff batt and to promote wicking. Whereas these techniques resulted in an improved product, the paper-like densified skin and/or the densified regions tend to stiffen the fluff batt and it is known that the densified regions are of reduced liquid holding capacity.
All of the known disposable diapers are laminated products wherein adhesive or glue is required to adhere one layer of the product to another layer. The adhesive or glue also lends thickness to the product and hence can make the product less flexible. Furthermore, the adhesive or glue detracts from the absorbent capacity of the product. In addition, the products that have been made do not have extensibility. Consequently, several sizes are necessary for each product line so that as the infant grows, or in the case of an adult product, the varying sizes can be accommodated in a product that is of an appropriate size.
Attempts have been made to place elastic in disposable diaper products both to improve the fit and to permit a wider range of sizes to be accommodated by one product line. Though products with elasticized leg portions have appeared in the marketplace the basic problem of having to provide several sizes in a product line has not been overcome. Furthermore, the products currently in the marketplace are made with adhesive lines or glue lines in order to satisfactorily laminate the product.
The present invention provides a product with a cloth-like backing which can be extended to accommodate more than one size.